For the first time in history, astronomers have detected a radio signal coming directly from an exoplanet — a planet orbiting a star beyond our Solar System. The signal was traced to Beta Pictoris b, a young gas giant roughly 63 light-years from Earth, and it is already rewriting what scientists know about the magnetic environments of distant worlds.
The discovery, reported in a preprint posted to arXiv on September 15, 2026 by Kevin Ortiz Ceballos of the Harvard & Smithsonian Center for Astrophysics and colleagues, used South Africa's MeerKAT radio telescope array to isolate repeating radio bursts unambiguously from the planet itself. It is not a message from aliens — the signal comes from the planet's auroras, the same kind of phenomenon behind Earth's northern and southern lights.
What Astronomers Detected From Beta Pictoris b
Across four observing sessions between February 2025 and May 2026, MeerKAT's 64 dishes recorded rapid, repeating radio bursts between 0.85 and 3.5 gigahertz, along with persistent background emission. The bursts showed strong circular polarization — the telltale signature of electron cyclotron maser emission, a process in which energetic electrons spiral along magnetic field lines.
Beta Pictoris b is no ordinary world. First discovered in 2008 with ESO's Very Large Telescope, it is a gas giant 9 to 13 times the mass of Jupiter, orbiting its star at eight times the Earth–Sun distance. Its system is only about 23 million years old — a newborn by cosmic standards — and the planet completes a full orbit roughly every 24 years. Scientists believe the intense magnetic field is likely powered by the planet's extremely fast spin: a single day on Beta Pictoris b lasts just 8 to 9 hours.
How MeerKAT Proved the Signal Came From the Planet
Earlier claimed detections of exoplanet radio emission could never be fully separated from the host star's own radio output. This time, the team used distant quasars as fixed reference points in the sky and tracked the emission over multiple sessions — proving it moved with the planet, not the star. "The most massive planet in the system, Beta Pictoris b, reaches an angular separation of up to 0.55 arcseconds across its 24-year orbit, and the host star is magnetically quiet, making the system an ideal target for radio observations," said Ortiz Ceballos.
"We attribute the radio emission to magnetosphere-ionosphere coupling at Beta Pictoris b," the researchers wrote in the preprint — the same mechanism behind auroral radio bursts from Jupiter, Earth, Saturn, Uranus and Neptune. The result marks the first time radio emission has been unambiguously traced to an exoplanet rather than its host star.
A Magnetic Field Thousands of Times Stronger Than Earth's
The highest detected frequency of the bursts let the team make the first direct measurement of an exoplanet's magnetic field. At the emission site it reaches at least 1,250 gauss — roughly 2,500 times stronger than Earth's ~0.5-gauss surface field and vastly beyond Jupiter's strongest regions. Exoplanet magnetic fields have been one of astronomy's great unmeasured quantities; they matter because a magnetic field can shield a planet's atmosphere from being stripped away by stellar winds, a factor in long-term habitability.
What This Exoplanet Radio Discovery Means
The finding is reported in a preprint that has not yet undergone peer review, so independent confirmation will matter. But if it holds, astronomers have gained a completely new way to study distant worlds: listening for their auroras to weigh their magnetic fields, map their atmospheres and probe how they interact with their stars. Decades of hunting for exoplanet radio emission have finally paid off — and Beta Pictoris b is unlikely to be the last planet we hear from.